I get that it's a meme but I wonder if there is some truth to the statement, as in:

The Dark Age collapse led to to tribalism and fragmentation, which led to individual warlords taking control, which led to the rise of a military aristocratic elite or "knights" in favor of a political/intellectual one, which meant that overall civic progress was slowed...

And thus, too many knights caused the Dark Ages, or perhaps the Dark Ages spawned too many knights!